WO2020011500A1

WO2020011500A1 - Fluid line

Info

Publication number: WO2020011500A1
Application number: PCT/EP2019/066103
Authority: WO
Inventors: Carolin Kohl; Christoph Steinkamp; Andreas Bauer; David Schoumacher; Olivier Piovesan
Original assignee: Norma Germany Gmbh
Priority date: 2018-07-09
Filing date: 2019-06-18
Publication date: 2020-01-16
Also published as: EP3820692A1; KR20210010575A; US20210252822A1; CN112236294B; JP2021531431A; KR102472712B1; DE102018116567A1; CN112236294A; EP3820692B1; DE102018116567B4; US11220084B2; JP7150129B2

Abstract

In the case of a fluid line (10) comprising a pipe (12) of a multilayered plastics material, wherein the pipe (12) surrounds an interior space (14), it is provided that the pipe (12) has an inner, first layer (16) of polyamide 9T (PA9T), a second layer (18) of polyamide 12 (PA12), a third layer (20) of polyamide 612 (PA612), a fourth layer (22) of polyamide 6 (PA6) and an outer, fifth layer (24) of polyamide 612 (PA612), wherein the inner, first layer (16) bounds the interior space (14). Consequently, the invention provides a fluid line (10) that has a reduced dissolution of material, a reduced permeability to volatile substances and nevertheless sufficient mechanical properties for a connection to other components of a line.

Description

fluid line

The invention relates to a fluid line with a tube made of a multilayer plastic material, the tube surrounding an interior.

Lines for the transport of chemically active fluids, such as. B. fuels in vehicles, must meet specific requirements during use. So the material of the pipe must not be dissolved by the fluid. This should also be avoided at higher temperatures. Furthermore, the line for the transported fluid and its chemical components must be impermeable so that volatile substances which may be contained in the fluid cannot penetrate through the wall of the line. On the one hand, this is to avoid a reduction in the quality of the transported fluid and, on the other hand, to prevent the volatile substances from escaping into the environment. Wash-out should also be avoided. This is particularly relevant when the fluid is in the line, ie when the fluid is not transported at least temporarily. The lines must also have mechanical properties have that allow a simple and safe connection of the line with other line components.

EP 2 066 494 B1 discloses a multilayer motor vehicle fuel delivery line, comprising an innermost first layer with a polyamide resin (nylon 9T) which is formed from a carbon dioxide component and a diamine component, a second layer made from polyamide 6 (PA6) , a third layer made of a copolyamide (CoPa) -based coupling layer and an external fourth layer made of polyamide 12 (PA12).

The object of the invention is to provide a fluid line of the type mentioned at the outset which has a reduced washout of the materials of the fluid line, a reduced permeability of volatile substances and yet has adequate mechanical properties for connection to other components of a line.

Main features of the invention are set out in the characterizing part of claim 1. Embodiments are the subject of claims 2 to 10.

To achieve the object, in the case of a fluid line with a pipe made of a multilayer plastic material, the pipe surrounding an interior, it is provided that the pipe has an inner, first layer made of polyamide 9T (PA9T), a second layer made of polyamide 12 (PA12), has a third layer of polyamide 612 (PA612), a fourth layer of polyamide 6 (PA6) and an outer, fifth layer of polyamide 612 (PA612), the inner, first layer defining the interior.

The invention thus provides a pipe for a fluid line which has a multilayer pipe wall. The tube surrounds an interior through which the fluid to be transported is guided. The inner, first layer directly borders and delimits the interior. The inner, first layer is made of polyamide 9T (PA9T). This material provides a layer that has low permeability. In particular, it forms a barrier against volatile substances in the fluid, such as alcohols or certain additives in fuels. The inner, first layer is also resistant to chemicals and hydrolysis and only absorbs small amounts of water. Leaching occurs at most to a small extent. Even at high temperatures, the inner, first layer has good mechanical properties Properties so that it is dimensionally stable. The inner, first layer thus forms a barrier for substances exiting the project, the barrier nevertheless ensuring adequate mechanical stability of the inner wall of the tube.

The second layer made of polyamide 12 likewise has only a low water absorption, so that the second layer forms an additional barrier against escaping water. Furthermore, the second layer is mechanically stable and improves the stability of the pipe even at high pressures or other mechanical forces.

The fourth layer polyamide 6 is highly available and relatively inexpensive. The fourth layer of polyamide 6 forms a basic structure for the pipe of the fluid line.

The outer, fifth layer of polyamide 612 has good media resistance to greases, oils, fuels, hydraulic fluids, water and alkalis. If the fluid line is used in an environment in which these substances can reach the outer layer of the pipe, the inner layers are protected by the outer, fifth layer. The outer, fifth layer thus forms a protective layer against external influences for the inner layers. Furthermore, the outer, fifth layer is elastic.

By combining the five layers in the tube of the fluid line, the tube has improved properties for the transport of fluids compared to the prior art, which have, for example, volatile substances or aggressive chemical substances. The pipe is nevertheless mechanically stable and elastic due to the multilayer plastic material. The individual layers support each other and combine their properties synergistically in such a way that the good chemical resistance also provides good mechanical properties in order to use the fluid line in different situations that have different requirements. The mechanical properties enable a safe and simple connection of the fluid line to other components of the line.

The inner, first layer can have a thickness in the range of 15% to 25%, preferably 20%, of the total wall thickness of the tube. An inner, first layer, which has this relative thickness, maintains the properties of the inner, first layer with regard to the impermeability to the substances which can escape from the fluid arranged in the interior. The second layer can have a thickness in the range from 2% to 18%, preferably 10%, relative to the total wall thickness of the tube. The second layer thus has a relative thickness, which acts in combination with the inner, first layer. Furthermore, this thickness already increases the mechanical stability of the pipe.

The third layer can have a thickness in the range from 2% to 18%, preferably 10%, relative to the total wall thickness of the tube. This relative layer thickness results in an increase in the tensile and bending strength of the pipe.

The fourth layer can comprise a thickness in the range of 30% to 50%, preferably 40%, relative to the total wall thickness of the tube. With this relative layer thickness, a basic framework for the fluid line is provided which is inexpensive but nevertheless gives mechanical stability.

The outer, fifth layer can have a thickness in the range of 12% to 28%, preferably 20%, relative to the total wall thickness of the tube. The outer protective layer which is formed from the outer, fifth layer can thus provide adequate protection against external, in particular chemical influences for the inner layers, a relatively small amount of material being used in comparison with the other layers.

For example, the outer, fifth layer can preferably additionally have color granules. In this way, the outer, fifth layer can be colored. The remaining portion of the outer, fifth layer can also be formed by other substances that slightly change the physical properties of the outer fifth layer. The basic properties of the outer, fifth layer are essentially not changed by the color granulate and / or the additives.

Furthermore, the use of a fluid line according to the preceding description for delivering fuel in a vehicle is provided to achieve the object.

The effects and advantages of using a fluid line result from the description of the fluid line given above. Further features, details and advantages of the invention result from the wording of the claims and from the following description of exemplary embodiments with reference to the drawings. Show it:

Fig. 1 is a schematic representation of a fluid line; and FIG. 2 shows a sectional view through the fluid line from FIG. 1.

A fluid line 10 is shown in FIGS. 1 and 2, which can be a fuel line in a vehicle, for example. The fuel can contain alcohol or other volatile substances or aggressive chemicals. The fluid line 10 can form at least a portion of the fuel line between the fuel tank and the engine of a vehicle.

According to FIG. 1, the fluid line 10 comprises a tube 12 which encloses an interior 14. The interior 14 extends through the entire tube 12 and has through openings 26 at the ends of the tube 12. The tube 12 can be connected to further line elements of the fuel line or another line, so that the passage openings 26 form a transition from the interior to the lumens of further line elements.

The fluid to be transported is then introduced through one of the through openings 26 into the interior 14 of the tube 12 and out through the other through opening 26.

The tube 12 is made of a plastic material that is constructed in multiple layers. This means that the tube 12 has a tube wall which has different materials in layers.

FIG. 2 shows a cross section through the fluid line 10. The tube 12 of the fluid line 10 comprises five layers.

The inner, first layer 16 forms the inner wall of the tube 12, which delimits the interior 14. The inner, first layer 16 comprises polyamide 9T (PA9T). The inner, first layer 16 can consist entirely of polyamide 9T. The inner, first layer 16 made of polyamide 9T has a low solubility and a low permeability for most substances, in particular for fuels and their components and additives. It also forms a barrier against water leakage. The inner, first layer 16 thus forms a barrier against one Passage of chemical components and further provides protection for the remaining sections of the tube 12, which could be dissolved by the components of the fluid, in particular of fuels.

In the example shown in FIG. 2, the inner, first layer 16 has a thickness which forms 15% to 25% of the total wall thickness of the tube 12.

The second layer 18 comprises polyamide 12 and extends around the inner, first layer 16. The second layer 18 further reduces the leakage of water from the inner, first layer 16. The second layer 18 further reinforces the mechanical properties of the tube, so that fluids can be transported through the fluid line 10 under a high pressure, if necessary.

In this example, the second layer 18 has a thickness that forms 12 to 18% of the total wall thickness of the tube 12.

The third layer 20 comprises polyamide 612 and extends around the second layer 18 and thus also around the inner, first layer 16. The third layer 20 adjoins the second layer 18 when viewed from the interior 14.

The third layer 20 increases the tensile and bending strength of the tube 12 and is nevertheless wet-strength and elastic. The third layer 20 thus further increases the stability of the tube 12.

In this example, the third layer 20 can have a thickness that forms 2% to 18% of the total wall thickness of the tube 12.

The fourth layer 22 comprises polyamide 6 and, with a layer thickness which in this example comprises 30 to 50% of the wall thickness of the tube 12, forms the basic structure of the tube 12. The fourth layer 22 is mechanically almost as stable as by the polyamide 6 the other layers while being highly available and relatively inexpensive. In combination with the other layers, the costs of the pipe can be reduced without sacrificing the physical properties required.

The fourth layer 22 extends further around the third layer 20 and thus also around the second layer 18 and the inner, first layer 16. The outer, fifth layer 24, like the third layer 20, has polyamide 612. The fifth layer 24 extends around the fourth layer 22 and thus around the other layers. It forms the outermost layer of the tube 12 and thus delimits the tube 12 from the environment.

The polyamide 612 means that the outer, fifth layer 24 is insensitive to most substances that are used, for example, in a vehicle. Escaping these substances from the corresponding overlying or adjacent pipelines and wetting the outer, fifth layer 24 with these substances therefore has no consequences for the outer, fifth layer 24 which affect the physical properties of the pipe 12. The outer fifth layer 24 thus forms a protective layer for the four inner layers 16, 18, 20 and 22.

In this example, the thickness of the outer, fifth layer 24 is 12% to 28% of the wall thickness of the pipe 12. This ensures adequate protection of the layers lying on the inside.

Furthermore, the outer, fifth layer 24 can have a mixture of polyamide 612 and a color granulate. The outer, fifth layer 24 can thus correspond to the color of the

Color granules are colored without the physical properties of the polyamide 612 being disturbed by the color granules.

In addition to the polyamide 612, the outer, fifth layer 24 can have color granules and / or other additives.

The materials of the layers with the layer thickness proportions are listed in a table below. The layer with the number 1 in the table is the inner, first layer 16 and the layer with the number 5, the outer, fifth layer 24. The layers with the numbers 2, 3 and 4 in the table therefore correspond to those Layers 18, 20 and 22.

Depending on the layer thicknesses, a fluid line 10 with a tube 12 can be provided, in which the inner, first layer 16 has a thickness in the range of, for example, 0.1 mm and 0.3 mm, preferably 0.2 mm. The second layer 18 can then have a thickness in the range from 0.01 mm to 0.2 mm, preferably 1 mm. In this case, the third layer 20 can also have a thickness in the range from 0.01 mm to 0.2 mm, preferably 1 mm. Furthermore, the fourth layer 22 can have a thickness in the range from 0.3 mm to 0.5 mm, preferably 0.4 m. Furthermore, the fifth layer 24 can then have a thickness in the range from 0.1 mm to 0.3 mm, preferably 0.2 mm.

The invention is not limited to one of the above-described embodiments, but can be modified in many ways. All of the features and advantages arising from the claims, the description and the drawing, including constructive details, spatial arrangements and procedural steps, can be essential to the invention both individually and in a wide variety of combinations.

Reference character list

10 fluid line

12 pipe

14 interior

16 inner, first layer

18 second layer

20 third shift

22 fourth shift

24 outer, fifth layer

26 passage opening

Claims

Patent claims

1. Fluid line (10) with a tube (12) made of a multilayer plastic material, the tube (12) surrounding an interior (14), characterized in that the tube (12) has an inner, first layer (16) made of polyamide 9T (PA9T), a second layer (18) made of polyamide 12 (PA12), a third layer (20) made of polyamide 612 (PA612), a fourth layer (22) made of polyamide 6 (PA6) and an outer, fifth layer (24 ) made of polyamide 612 (PA612), the inner, first layer (16) delimiting the interior (14).

2. Fluid line according to claim 1, characterized in that the inner, first layer (16) has a thickness in the range from 15% to 25%, preferably 20%.

3. Fluid line according to claim 1 or 2, characterized in that the second layer (18) has a thickness in the range from 2% to 18%, preferably 10%, of a wall thickness of the tube (12).

4. Fluid line according to one of the preceding claims, characterized in that the third layer (20) has a thickness in the range from 2% to 18%, preferably 10%, of a wall thickness of the tube (12).

5. Fluid line according to one of the preceding claims, characterized in that the fourth layer (22) has a thickness in the range from 30% to 50%, preferably 40%, of a wall thickness of the tube (12).

6. Fluid line according to one of the preceding claims, characterized in that the outer, fifth layer (24) has a thickness in the range from 12% to 28%, preferably 20%, of a wall thickness of the tube (12).

7. Fluid line according to one of the preceding claims, characterized in that the outer, fifth layer (24) additionally has a color granulate.

8. Use of a fluid line (10) according to one of the preceding claims for conveying fuel in a vehicle.